Method of making skis



\ March 13, 194.5.. l. MARKS 2,371,305

Y METHOD OF MAKING SKIS Filed sept. 22, 1941 es W,

Patented Mar. 13, 1945 UNITED STATES PATENTv OFFICE l Y 2,371,305 iMETHOD MAKING SKIS Isidore Marks, Boston; Mass.

Application September 22, 1941, Serial No. 411,845

4 Claims.

This invention relates to improvements in skis and the method of makingthe same, and Vmore specifically relates to improvements in themanufacture of skis of the laminated type. Heretofore laminated skishave been made by assembling layers of stock which are glued together,the middle layer or one of the central layers being made shorter thanthe other layers and tapering in thickness from its ends towards themid-portion thereof.. This central layer provides the increasedthickness at the middle of the ski which imparts the additional strengthfor holding the usual footfattachments. Such prior skis, to aconsiderable extent, require in dividual pressing and finishingoperations.

It is an object of my invention to provide improvements in the methodsof `manufacturing skis which will reduce the cost of manufacture byenabling the pressing of a number of skis at one time to impart thelongitudinal curvature to the skis.

More specifically itis an object of my invention to prepare the roughski blanks by assembling several layers of stock which are of uniformthickness throughout the length of the ski whereby the ski blanks areilat on the top and bottom surfaces and a numberI of such blanks may besuperposed in a pile and pressed simultaneously.

It is further an object of my invention to make a rough ski blank byassembling three layers of slots cut in the stock, the top layerterminating short of the toe portion while the middle and bottom layersextend the full length of the ski, the layers of stock being gluedtogether except at the toe portions Where the middle and bottom layersare left unglued; such rough blanks being superposed in a pile andpressed to impart the longitudinal curv-` so manufactured in which thebottom layers of the ski are substantially uniform in thicknessthroughout the length of the ski while the top layer of the ski isshaped to taper from its ends towards the middle thereof and preferablyterminates short of the toe portion of the ski.

Further objects and advantages of my improvements will be morereadilyapparent from thefollowing description of preferred embodimentsthereof as illustratedv in the attached drawing in which:

Fig. 1 is a planview of a finished ski made in accordance with myinvention;

Fig. 2 is a side elevation of the ski shown in Fig. l;

Fig. 3 is a plan view ofl an assembled blank from which the ski is made;

Fig. 4 is a vertical longitudinal section taken on theplane indicated 44 in Fig. 3;

Fig. 5 is a vertical cross-section taken on the plane indicated 5--5 inFig. 3;

Figs. 6, '7 and 8, are sectional views similar to Fig. 5 butillustrating modied constructions;

Fig. 9 is a plan view of a ski blank showing upper layer thereoi'tofacilitate bending; Fig. 10 is a vertical longitudinal sectional viewtaken on the plane indicated llll0 in Fig. 9;

Fig. 1l. is a side elevation of a ski blank after the first bending orpressing operation has been performed; Y Fig. l2 is a side elevation Aofthe ski blank after the cutting or planing operation has been performed,showing the tip ends spread apart and diagrammatically illustrating theplacing ofl a sheet of glue between the spread ends;

Fig. 13 is a longitudinal section taken through a pile of ski blanks andillustrating the die members for performing the first bending orpressing operation; and i Fig. 14 is a fragmentaryvertical section takenthrough the tip end of the ski and showing the second pressing operationfor bending the tip end.

It Ahas now become commercial practice to have skis of laminatedconstruction. `In such prior practice the ski has been made of threelayers, the top and bottomlayers extending the full length of the skiand being of uniform thickness throughout the length thereof while themiddle layer or one of the middle layers is shorter than thelength ofthe ski` and tapers from its ends towards the middle thereof to providethe increased thickness for the central portion of the ski where theshoe is attached. e

In my novel construction the ski blank is composed ofthree layers Ill,I2 andY I4, the bottom layer ID and the middle. layer l2 extending thefull length of the ski and `substantially of uniform thickness.throughout thelength of the ski.

The rough blank. from which the Ski is madey is disclosed in Figs. 3, 4and2. The entire bottom surface of the top layer I4 is glued to the topsurface of the middle layer I2. I'he layers I0 and I2 are glued togetherfrom the heel end of the ski to a point adjacent the end of the toplayer I4 leaving the tip end portions I6 and I8 of the layers I and I2respectively unglued. It will be understood that any one or several ofthe layers I0, I2 and I4 may be made of builtup construction bylaterally gluing together strips which extend longitudinally of the ski.

Fig. 6 shows the bottom layer .I0 composed of a plurality of strips 20.'It will be understood that the bottom layer I0, if made up of separatepieces as in Fig. 6, is relatively thin and will not permit planing ofthe running face of the ski after the ski has become worn. The middlelayer I2 may similarly be made up of a plurality of strips gluedtogether in a lateral direction of the ski, such as the strips 22 shownin Fig. 7. This construction may be preferable to that of Fig. 6 sincethe glued seams between the pieces 22 will be covered by the solidbottom layer I0 and by the solid top layer I4 except at the top surfaceof the tip end of the ski. The top layer I4 could also be made up of aplurality of pieces 24 as shown in Fig. 8.

If the top layer I4 is relatively thick it may be found desirable to cutslots in the top layer to facilitate bending thereof as illustrated inFigs. f

in subsequent operations the block or layer I4 will be planed away atits ends to a finished surfacebelow the bottom of the slots.

Since the rough blanks are flat on the top and bottom surfaces thereofthey may be placed in a pile as shown in Fig. 13 so that the firstbending or pressing operation may be performed upon a number of theblanks at one time. 4Thus the pile of rough blanks in Fig. 13 may bepressed between the bottom die member 28 and the top die member 30 andthe blanks held under presv sure so as to impart the longitudinalcurvature to the ski blanks. It will be understood that during thisfirst pressing operation the free ends I6 and I8 of the layers I0 and I2are still unglued and are no t," shaped in the press. The ski blankafter the ffrst pressing operation has been performed is shown in Fig.11.

The next step is to perform the planing and trimming operations on thepressed blank. The cutting or planing may be conveniently performedeither by machine or by hand since the tip end of the ski has not yetbeen bent. Fig. 12 is a side elevation of the ski after the planingoperation. It will be noted that the front and rear portions of the toplayer I4 have been cut down so that the ends of the blank are relativelythin and taper towards the thick central portion.

The tip end ofthe ski may then be glued and shaped. A convenient mannerof gluing the ends I6 and I8 of the layers I0 and I2 is `to spread theends I6 and I8 and slip in a sheet of glue, such as a sheet of resin orresin-impregnated paper, although liquid glue may be used if desired.

The toe portion may be then be shaped by the presser members 34 and 36as shown in Fig. 14. These presser members may be heated so as to skiblank to shape the blank with the ends melt the glue and cause bondingof the layers of the toe portion at the same time as the shaping. Theskis may be nished in any desired manner after the toe has been shaped.

The novel method of manufacturing skis disclosed herein will materiallyreduce the cost of manufacture and will permit the use of automaticmachines, thus eliminating hand operations. The making of rough blanksas disclosed enables the pressing of a plurality of ski blanks at onetime. The planing of the blanks can more readily be carried out bymachine when performed before shaping the toe end-of the ski.Furthermore, it is relatively less expensive to cut andplane the toplayer of theV rough blank as disclosed rather than to fit a speciallyshaped middle layer between the top and bottom layers of a ski.

I claim:

l. The method of making a laminated ski which consists in providingthree pieces of stock, each piece being uniform in thickness throughoutthe length thereof, one of said pieces being shorter and thicker thanthe other two pieces, gluing said pieces together to `form a blank withthe short piece on top and terminating short of the toe portion of theblank, the'toe portions of the two bottom layers being left unglued,pressing the assembled blank so as to impart a longitudinal curvaturethereto, planing the short top layer ofthe blank, then gluing andpressing the toe portions of the two bottom layers.

2. The method of making a laminated ski which consists in gluingtogether a pair of laminations which extend the full length of the skibut leaving the toe portions of said laminations unglued, then gluing tothe top surface thereof a third lamination which extends from the heelend of the ski t0 a point short of the toe portion, then pressing saidassembled laminations to impart a longitudinal curvature thereto, thenplaning the top lamination, then gluing and pressing the toe portions ofthe first pair of laminations.

3. The method of manufacturing skis which consists in preparing a skiblank having a plurality of laminations, each of said laminationsV beingof uniform thickness throughout the length thereof, the laminationsbeing glued together except at the toe portion of the blank, pressingthe ski blank to impart a longitudinal curvature thereto, then planingthe top lamination of the thicker than an intermediate portion thereofand then gluing and pressing to shape the toe portion of the blank.

4. The method of. manufacturing skis which. consists in assembling threelayers of stock, each layer being substantially uniform in thicknessthroughout the length thereof, said three layers being glued together toform a rough blank having fiat top and bottom surfaces, superimposing aplurality of such blanks in a pile, the individual blanks beingunsecured with respect to each other-,

and then pressing the pile of blanks to simultane-. ously impart alongitudinal curvature to all thel .blanks in the pile, then cutting andtrimming the top layer of each of the ski blanks whereby said top layerdecreases in thickness from its central vportion towards the endsthereof, then sepa-l rately pressing the toe portions of the individualblanks and finishing the skis. Y

ISIDORE MARKS.

